//
//  MainTabBar.swift
//  sinaweibowj
//
//  Created by Macintosh on 15/12/12.
//  Copyright © 2015年 mactoinsh. All rights reserved.
//

import UIKit

class MainTabBar: UITabBar {
    
    //uiview的默认构造方法
    //重写父类的构造方法
    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubview(composeBtn)
    }
    
    required init?(coder aDecoder: NSCoder) {
        // fatalError("init(coder:) has not been implemented")
        super.init(coder :aDecoder)
        addSubview(composeBtn)
    }
    
    //在这个方法中设置所有子视图的frame
    override func layoutSubviews() {
        
        super.layoutSubviews()
        //修改frame
        let w = self.bounds.width/5
        let h = self.bounds.height
        let rect = CGRect(x: 0, y: 0, width: w, height: h)
        
        //遍历所有子视图修改大小
        var index: CGFloat = 0
        for subview in subviews {
            
            if  subview.isKindOfClass(NSClassFromString("UITabBarButton")!){
                
                subview.frame = CGRectOffset(rect, index * w, 0)
                
                //三目
                index += (index == 1 ? 2 : 1 )
            }
        }
        
        //设置加号按钮的位置
        composeBtn.frame = CGRectOffset(rect, w * 2, 0)
        bringSubviewToFront(composeBtn)
    }
    
    //懒加载加号按钮
    lazy var composeBtn:UIButton  = UIButton(imageName: "tabbar_compose_icon_add" , backgroundImageName:"tabbar_compose_button")

    
}
